Global environmental problems including global warming are recently being seriously studied throughout the world. It is necessary to actively promote the use of clean natural energy.
The use of natural energy typically includes photovoltaic power generation, wind power generation, and wave-activated power generation. Photovoltaic and wind power generation are commercially available. However, the production of solar panels involves significant costs. In Japan, where earthquakes and typhoons frequently occur, wind power generation plants must be constructed with extra strength. Vast land areas are required to construct large-scale wind power generation farms.
As Japan is an island nation surrounded by the sea on all sides, wave power generation is a promising energy source. Wave power generation is being actively studied in Japan but the technology has not yet reached commercial levels.
Various systems for wave power generation have been proposed and experiments conducted. Many of these systems utilize the vertical motion of waves to create a flow of air or water, with the flow guided through a duct to rotate a turbine (Kokai Tokkyo Koho (Publication of unexamined patent applications) No. 6-280240 (1994) and 5-164036 (1993), etc.). Small-sized floating power generators based on these inventions have already been put to commercial application as navigation aids. Experiments on large-sized floating wave power generators currently underway include Kaimei (80 m in total length, 12 m in width, and weighing 800 tons) of the Japan Marine Science and Technology Center and, the stationary type Sanze model (Research Development Corporation of Japan, etc.).
Wave-activated power generators using fluids, such as those mentioned above, are generally inefficient at generating electric power because of the severity of existing conditions like wave magnitude. Improving efficiency requires increasing the size of the system, which in turn means significant investments that the system uneconomical.
The present invention intends to solve the above problems by offering a small-sized and efficient wave-activated power generator. According to the present invention, the motion of a floating body on the sea is converted into energy by a control moment gyro to generate power. A wave suppressor using said power generator is also offered.
The wave-activated power generator of the present invention comprises an enclosed gimbal, a flywheel which is set in the gimbal and turns on the spin shaft that is mounted at right angles to the gimbal shaft, a spin motor to turn the flywheel at high speed, and a power generator connected to the gimbal shaft via a gearing to increase speed, wherein the motion of the floating body produced by wave action is used to turn the gimbal to generate power. The system of the present invention is provided with a sensor to detect the inclination and angular velocity of the floating body and an encoder to detect the rotational angle and position of the gimbal. Signals from the sensor are used to synchronize the motion of the floating body with the rotation of the control moment gyro body for more efficient power generation. The efficiency of power generation is further enhanced by matching the gimbal rotation to the wave motion, which is basically a circular motion.